For many years the transportation industry has been concerned with designing reinforced structural members or assemblies that do not add significantly to the weight of a vehicle. For example, U.S. Pat. Nos. 5,755,486; 4,901,500; and 4,751,249 describe prior art reinforcing devices. Generally, the reinforced structural members have used expandable materials combined with other materials for forming structural members that fit into one or more cavities of an automotive vehicle. Once the structural members are placed in the cavities the expandable materials may be expanded to secure the members in the cavities. Typically, it is desirable to maintain some degree of control over the amount of expansion experienced by the expandable materials since the amount of expansion may at least partially dictate the structural or strength properties exhibited by the materials. However, such control may be difficult since cavities of automotive vehicles tend to vary in size due to factors such as size tolerances of vehicle components and the like.
In addition to variability in size, the shapes of the cavities can cause difficulties in forming structural members that fit properly in the cavities. Moreover, the sizes of openings through which the structural members are inserted to place the structural members in the cavities may be relatively small, which may cause assembly problems for the structural members. Thus, there is a need for a reinforced structural assembly that can be effectively used in cavities that have various shapes, various sizes, variably sized openings or a combination thereof.